<I>Psenes</I> <I>Cyanophyrs</I> Cuvier and Valenci

BULLETIN OF MARINE SCIENCE OF THE GULF AND CARIBBEAN

VOLUME 6 1956 NUMBER 3

A CONTRIBUTION TO THE LIFE HISTORY OF THE NO MElD FISH PSENES CYANOPHYRS

CUYlER AND VALENCIENNES. I

VIRGINIA A. LEGASPI Bureau of Fisheries, Manila, P. J.

ABSTRACT Thirty postlarval, juvenile and adult specimens of Psenes cyanophrys Cuvier and Valenciennes, ranging from 2.5 to 66.0 mm standard length, from the Straits of Florida and the Caribbean Sea, are described and six are illustrated. Changes during development, spawning and spawning areas, and general biology are discussed.

INTRODUCTION The most common nomeid fish taken in surface hauls in Florida and Caribbean waters is Psenes cyanophrys Cuvier and Valenciennes. The present work is confined to the study of a series of 30 postlarval and juvenile specimens of this species contained in the collections of the Marine Laboratory of the University of Miami. This paper is one of a series published as results of investigations carried out since 1953 by the National Geographic Society-Marine Laboratory, University of Miami, Pelagic Fish Life History program under the direction of Dr. Gilbert L. Voss. The author wishes to thank the National Geographic Society for the financial assistance which made this work possible and the Marine Laboratory for the facilities and specimens placed at her disposal. She is deeply grateful to Dr. Gilbert L. Voss for his supervision and guidance in the course of this study, and to Dr. C. P. Idyll, Dr. Hilary B. Moore, and Mr. Luis R. Rivas for their valuable criticisms and suggestions. In addition she wishes to thar k the captain and crew of the research vessel PHYSALIA for the collection of the material used in this study and Mrs. Nancy A. Voss and Mrs. Joan F. Clancey for sorting the larvae to family. Finally she wishes to lContribution No. 158 from the Marine Laboratory, University of Miami. 180 Bulletin of Marine Science of the Gulf and Caribbean [6(3) thank Dr. Leonard P. Schultz, Curator of Fishes, United States National Museum, for reading the manuscript and for his valuable criticisms and suggestions. This work was carried out under a Ful- bright Fellowship while the author was on leave of absence from the Bureau of Fisheries, Philippine Government.

MATERIALS,METHODSANDTERMINOLOGY The majority of the specimens were obtained from the surface by means of dip nets and plankton nets at stations (Table 1) in the

TABLE 1 STATIONDATA OF THIRTY POSTLARVALANDJUVENILESPECIMENSOF Psenes cyanophrys CUVIERANDVALENCIENNES. Station Date Time Location Depth Temp. Sal. No.oj M °C %0 specimens 10 4/ 2/54 0300 23°49'N,82°31'W 0 27.10 -- 6 74 4/11/54 1610 18°34'N,82°04'W 0 27.50 36.11 1 79 4/12/54 0100 18°04'N,82°41'W 0 26.67 36.13 1 84 4/12/54 0845 17°39'N,83°12'W 0 28.00 34.83 3 89 4/12/54 1700 17° 14'N, 83°49'W 0 27.40 36.24 10 SL14 B-O 3/19/53 2100 25°35'N,79°2YW 0 26.64 35.92 1 SL14 C-O 3/20/53 0055 25°35'N,79°25'W 0 26.64 35.92 1 SL18 B-O 7/12/53 0220 25c35'N,79°2YW 0 28.08 -- 1 SL19 B-O 8/14/53 2050 25°35'N,79°25'W 0 29.82 36.41 1 SL20 A-O 10/5/55 0430 10 mi. E. of Miami 0 28.80 -- I c NG32-398/15/51 0810 26?08'N,79 '56'W 0 ----- 2 Caribbean Sea, off Grand Cayman, and in the Straits of Florida (Figure 1) during an oceanographic survey of the area by the Marine Laboratory vessel PHYSALIAin connection with the Laboratory's Tropical Oceanography contract with the Office of Naval Research. The remaining material was taken from two routine stations in the Florida Current off Miami by the same vessel in the course of the fish larvae work and in conjunction with an earlier plankton investi- gation. The location occupied as the first routine station designated NG was about ten miles east of the Miami sea buoy on the west side of the Florida Current (25°53' to 26°08'N, 79°56'W) where the depth is over 100 fathoms. The other routine station designated SL was located on the east side of the Florida Current where there is an average depth of 740 meters. A description of the nets, number of hauls at each station, the hydrographic instruments used, and the methods of handling the collections has been given by N. Voss (1954). Complete data for 1956] Legaspi: Lite History of Psenes 181 87 84 81- 79

27 27

24 24

••

15 15 I ~ . ~- -~- --- 94 81 79- 87 -

FIGURE 1. Distribution map of Ps~nes cyanophrys Cuvier and Valenciennes studied in this work. the stations in the lower Straits of Florida and the Caribbean Sea have been given by Hela et al (1955), and for the NG stations by Miller et al (1953). 182 Bulletin of Marine Science of the Gulf and Caribbean [6(3) The terms LARVA, PROLARVA, POSTLARVA and JUVE- NILE are used as defined by Hubbs (1943). All illustrations are by the author.

MEASUREMENTS, PROPORTIONS AND COUNTS The smaller specimens, up to 9.4 mm, were measured with a micrometer eyepiece and the larger ones with a pair of dividers. Unless destroyed, the left side was used to make the counts and the lateral measurements. Total length, which has no apparent value in this study, was not taken. The definitions of measurements herein used were adapted from Voss (1954) all of which suited the present specimens. STANDARD LENGTH, in smaller specimens before the appearance of the urostyle, is measured from the tip of the snout to the tip of the vertebral column. In those specimens in which the urostyle is already formed, the measurement is to the middle of the caudal base. The DEPTH is measured at the origin of the pelvic fin. The HEAD is measured from the tip of the snout to the posterior edge of the membranous opercle, exclusive of projecting spines. The SNOUT is measured from the tip of the upper jaw to the anterior edge of the bony orbit. The ORBIT refers to the greatest horizontal diameter of the bony orbit, inside measurements. All measurements are given in millimeters. Proportions, or indices are expressed as a percentage of the standard length, but the snout length and orbit diameter are also expressed as percentages of the head length. Only fully formed spines and soft rays are included in the counts.

TAXONOMY AND DISTRIBUTION Psenes cyanophrys Cuvier and Valenciennes, 1833 Figures 2 A-C; 3 D-F. JUVENILE SYNONYMY. Psenes cyanophrys Cuvier and Valenciennes. Gunther, 1889: 12-13 (compares a small series of P. cyanophrys with other species of Psenes described by Cuvier and Valenciennes, 25.5-76.0 mm total length). Norman, 1927:350 (30.0 mm specimen, 3°46'00"N, 16°49'00"W). Weber, 1913: 152 (describes distribution of 10 specimens of P. cyanophrys, 16.0-85.0 mm from Celebes and Banda Seas). Longley and Hildebrand, 1941 :75 (150 specimens up to 120 mm picked up from wastes of a bird rookery in Tortugas, Florida). The genus Psenes has been referred to several families by different authors and the exact taxonomic position of the genus is not clear even now. In confusion of certain overlapping characters, various 19561 Legaspi: Life History of Psenes 183 authors have included the group in the families Carangidae, Stroma- teidae and Nomeidae. The genus Psenes was first described by Cuvier and Valenciennes (1833) and included five species: P. guamensis, P. javanicus, P. aur- atus, P. leucurus, and P. cyanophrys. The last was described from a single specimen, 5 inches long, from New Ireland, off northeast New Guinea. LUtkcn (1880) gave an account of young stages, not exceeding 87.0 mm, of P. cyanophrys. Together with Psenes maculatus, he recognized them as forms well distributed in the Atlantic Ocean. Day (1888), in his work on the fishes of India, Ceylon and Burma, described two species of Psenes with the carangids: P. indicus and P. javanicus. Jordan and Evermann (1896), Weber (1913) and de Beaufort and Chapman (1951) have recognized the latter as a synonym of P. cyanophrys. GUnther (1889), in his studies of the pelagic fish collection made by the CHALLENGER, through an examination of a long series of specimens, found that the several species of Psenes described previously by Cuvier and Valenciennes (1833) were actually Psenes cyanophrys whose distribution is pelagic in the tropical Atlantic, Pacific, and Indian Oceans. He listed a new species, P. arafurensis, and along with other occurring nomeids he included them in the family Nomeidae. Goode and Bean (1895) recorded two species of Psenes, but neither of them was P. cyanophrys. They were collected below 400 fathoms by the ALBATROSS at 32°-3rN, 73°-76°W, and placed in the family Nomeidae. Jordan and Gilbert (1882) according to Baldwin (1954, unpublished) stated that the Nomeidae contains five genera and ten species. They separated it from the carangids because of the increased number of vertebrae, and grouped it, because of the teeth in the pharynx, with the family Stromateidae. The family Nomeidae, according to Jordan and Evermann (1896), has 6 to 8 genera and about 15 species, mostly of the open seas, composed of small fishes rarely used as food. They added P. regulus Poey to their list of Psenes. Fowler (1906) described a new species, Psenes chapmani, which he placed in the family Nomeidae, which were taken from northwest of the Cape Verde Islands, from northwest of the Lesser Antilles and from the Sargasso Sea. He compared his types with an East Indian 184 Bulletin of Marine Science of the GuZf and Caribbean [6(3) form, Psenes guttatus, and with P. edwardsii Eigenmann. In his work on marine fishes of West Africa, Fowler (1936) himself synonymized P. chapmani with P. cyanophrys. Weber (1913), while examining the fish collection of the SIBOGA expedition, separated a small series of P. cyanophrys ranging in size from 16 mm to 85 mm taken from the surface waters of the Celebes and Banda seas. Psenes pacificus was one of the new species of fish described by Meek and Hildebrand (1925) from Panama. They noted this fish to be rather close to P. cyanophrys, and grouped it with the stroma- teids. In the marine fish collection of R. R. S. DISCOVERY, Norman (1930) recognized two species of Psenes: P. cyanophrys and P. pellucidus, which he listed in the family Stromateidae. The largest specimens of P. cyanophrys were recorded by Longley and Hildebrand (1941) with the family N omeidae in their catalogue of fishes of Tortugas. Specimens up to 120 mm were picked up from the wastes of a bird rookery, having been regurgitated together with Monacanthus hispidus, Trachurops crumenopthaZma and Caranx ruber. The combination indicated a pelagic habitat, possibly occurring about the Sargassum, where young Monacanthus hispidus and Caranx ruber are common. In the Indo-Australian archipelago, de Beaufort and Chapman ( 1951) recorded three nomeids including a new species, P. white- Zeggi, in the family Stromateidae. They noted that the young of this fish are pelagic, often in shoals, and the adults probably live in deep waters. These workers also recognized the other four species of Psenes described by Cuvier and Valenciennes (1833) to be synonyms of P. cyanophrys. In his checklist of Philippine fishes, Herre (1953) listed another species, P. extraneus, known from a single specimen bought in one of the local markets, probably used as food. He included the occurring species of Psenes under the family Nomeidae. From the brief survey of the literature, it is apparent that the genus Psenes is badly in need of taxonomic revision. Until this has been done, the differentiation of the various species of this genus is not feasible. The past records on the range of distribution of Psenes cyanophrys suggest a circumtropical occurrence, although stragglers, presumably, are reported as far north as Long Island (Hubbs, 1929) 1956] Legaspi: Life History of Psenes 185 and No Man's Land, off Martha's Vineyard (Miller, 1946). The postlarval and juvenile specimens included in this work were found to be conspecific with the specimens of Psenes cyanophrys Cuvier and Valenciennes described by Jordan and Evermann (1896, pp. 950-51, and de Beaufort and Chapman (1951, pp. 88-89, fig. 18). In Psenes cyanophrys, the preopercular margin with its mode of spination, and the general round appearance served to distinguish it from other carangoid and nomeid larvae with which it bears close resemblance in the postlarval stage. The fin ray counts and relatively small pelvic fins proved to be the most reliable distinguishing characters in the juveniles.

TABLE 2 MEASUREMENTS (IN MM) OF THIRTY POSTLARVAL AND JUVENILE SPECIMENS OF Psenes cyanophrys CUVlER AND VALENCIENNES. Station Standard Head Snout Eye Depth Length Length Length Diameter Yucatan, 89 2.5 .6 .1 .3 1.1 Yucatan, 89 3.2 1.2 .5 .5 1.6 SL 40 B-O 4.7 2.1 \ .6 .8 2.3 SL 25 A-O 6.9 2.7 .9 .8 3.1 SL 14 C-O 9.4 3.8 1.0 1.4 4.8 NO 32-39 17.0 6.0 1.6 2.4 9.0 Yucatan, 89 17.5 7.0 1.8 2.2 9.3 SL 14 B-O 18.0 6.5 1.5 2.5 10.0 SL 20 A-O 18.5 6.5 1.5 2.8 10.0 Yucatan, 79 18.5 7.0 1.6 2.8 10,0 SL 18 B-O 18.5 6.6 1.5 2.8 11.0 Yucatan, 89 19.0 8.0 1.8 2.6 11.0 Yucatan, 89 20.0 8.0 1.7 2.8 11.0 NO 32-39 21.0 8.0 2.0 2.8 11.8 Yucatan, 89 21.5 8.0 2.0 2.8 12.0 Yucatan, 10 21.5 9.0 2.2 3.0 13.5 Yucatan, 10 22.0 8.0 2.0 3.0 12.0 Yucatan, 89 22.5 8.0 2.1 3.0 12.0 Yucatan, 89 24.0 9.0 2.1 3.0 14.0 Yucatan, 89 25.0 9.0 2.0 3.2 14.0 Yucatan, 89 26.0 9.5 2.3 3.0 15.0 Yucatan, 10 33.0 11.5 3.0 4.0 16.0 SL 19 B-O 33.5 12.0 3.0 4.0 15.0 Yucatan, 10 37.5 13.0 3.5 4.5 18.0 Yucatan, 84 38.0 12.5 3.0 4.0 19.0 Yucatan, 10 40.0 13.5 3.5 5.0 19.0 Yucatan, 10 40.0 14.0 3.5 5.0 20.0 Yucatan, 84 43.0 14.5 3.5 5.0 20.0 Yucatan, 84 44.5 15.5 4.0 5.0 22.0 Yucatan, 74 66.0 il.0 5.0 7.0 32.0 186 Bulletin at Marine Science of the Gulf and Caribbean [6(3)

TABLE 3

SPINEY AND SOFT FIN RAY COUNTS OF THIRTY POSTLARVAL AND JUVENILE SPECIMENS OF Psenes cyanophrys CUVIER AND VALENCIENNES. ~tation Stand. Dorsal Fin Anal Fin Pectoral Pelvic Length Fin Fin

Yucatan, 89 2.5 Yucatan, 89 3.2 SL 40 B-O 4.7 15 2 SL 25 A-a 6.9 VII,27 lII,26 17 1,3 SL 14 CoO 9.4 X-I,27 III,26 18 1,5 NG 32-39 17.0 X-I,27 TIT,28 19 1,5 Yucatan, 89 17.5 IX-I,26 JII,27 19 1,5 SL 14 B-O 18.0 X-r,26 III,28 18 1,5 SL 20 A-O 18.5 X-I,26 III,28 20 1,5 Yucatan, 79 18.5 IX-I,28 lII,27 18 1,5 SL 18 B-O 18.5 X-I,26 lII,27 18 1,6 Yucatan, 89 19.0 X-I,27 III,27 19 1,5 Yucatan, 89 20.0 X-I,27 I1I,26 18 1,5 NG 32-39 21.0 X-I,27 I1I,27 18 1,5 Yucatan, 89 21.5 IX-I,26 I1I,27 18 1,5 Yucatan, 10 21.5 IX-I,27 IIl,26 18 1,5 Yucatan, 10 22.0 IX-I,27 m,27 19 1,5 Yucatan, 89 22.5 IX-I,26 IlI,27 18 1,5 Yucatan, 89 24.0 IX-I,26 IlI,27 19 1,5 Yucatan, 89 25.0 X-I,26 lII,26 18 1,5 Yucatan, 89 26.0 IX-I,26 m,27 18 1,6 Yucatan, 10 33.0 X-I,26 JII,27 18 1,5 SL 19 B-O 33.5 X-I,27 JII,27 18 1,5 Yucatan, 10 37.5 IX-I,26 I1I,26 19 1,5 Yucatan, 84 38.0 X.I,27 III,27 18 1,5 Yucatan, 10 40.0 IX-J,26 IlI,27 18 1,5 Yucatan, 10 40.0 X-I,26 III,27 18 1,5 Yucatan, 89 43.0 X-I,27 m,26 18 1,5 Yucatan, 89 44.5 X-I,26 II1,26 18 1,5 Yucatan, 74 66.0 X-I,26 II1,26 18 1,5 ------1956] Legaspi: Life History of Psenes 187 TABLE 4 BODILY PROPORTIONS OF THIRTY POSTLARVAL AND JUVENILE SPECIMENS OF Psenes cyanophrys CUVIER AND VALENCIENNES. Station Stand. Depth Head Snout Snout Eye Eye-Head Length Index Index Index Head Index Index Index Yucatan, 89 2.5 44.0 24.0 4.0 16.6 12.0 50.0 Yucatan, 89 3.2 50.0 37.5 18.7 41.0 15.6 41.0 SL 40 B-O 4.7 48.9 44.7 12.7 28.5 17.0 38.0 SL 25 A-O 6.9 44.9 39.1 13.0 33.3 11.6 29.6 SL 14 CoO 9.4 51.0 40.4 10.6 26.6 14.9 36.8 NG 32-39 17.0 52.9 35.2 8.1 25.7 14.1 40.0 Yucatan, R9 17.5 53.1 40.0 10.2 23.0 12.5 31.4 SL 14 B-O 18.0 55.5 36.1 8.3 23.0 13.8 38.4 SL 20 A-O 18.5 54.0 35.1 8.1 23.0 15.1 43.1 Yucatan, 79 18.5 54.0 37.8 8.6 22.8 13.5 35.7 SL 18 B-O 18.5 53.5 35.0 8.2 22.2 15.0 43.0 Yucatan, 89 19.0 57.8 42.1 9.4 22.5 13.6 32.5 Yucatan, 89 20.0 55.0 40.0 8.5 21.2 14.0 35.0 NG 32-39 21.0 56.1 38.1 9.5 25.0 13.3 35.0 Yucatan, 89 21.5 55.8 37.2 9.3 25.0 13.0 35.0 Yucatan, 10 21.5 62.8 41.8 10.2 24.4 14.0 33.3 Yucatan, 10 22.0 54.5 36.3 9.0 25.0 13.6 37.5 Yucatan, 89 22.5 53.3 35.5 9.3 26.2 13.3 37.5 Yucatan, 89 24.0 58.3 37.5 8.7 23.3 12.5 33.3 Yucatan, 89 25.0 56.0 36.0 8.0 22.2 12.8 35.5 Yucatan, 89 26.0 57.7 36.5 8.8 24.2 11.5 31.5 Yucatan, 10 33.0 48.4 34.8 9.0 26.0 12.1 34.7 SL 19 B-O 33.5 46.2 35.8 9.0 25.0 12.0 33.3 Yucatan, 10 37.5 48.0 34.6 9.3 27.0 12.0 34.6 Yucatan, 84 38.0 50.0 32.8 8.0 24.0 10.5 32.0 Yucatan, 10 40.0 47.5 33.7 8.7 26.0 12.5 37.0 Yucatan, 10 40.0 50.0 35.0 8.7 25.0 12.5 35.0 Yucatan, 84 43.0 46.5 33.7 8.1 24.1 11.6 34.4 Yucatan, 84 44.5 49.4 34.8 9.0 25.8 11.2 32.2 Yucatan, 74 66.0 48.4 31.8 7.5 23.8 10.6 33.3

DEVELOPMENT SPECIMENS STUDIED. Twenty-one specimens (2.5-66.0 mm standard length) from five stations in the Caribbean Sea and the Straits of Florida (complete data given in Table 1). Seven specimens (4.7-33.0 mm standard length) from seven SL stations (complete data given in Table 1). Two specimens (17.0-21.0 mm standard length) from two NG stations (complete data given in Table 1). From an array of carangoid and nomeid postlarvae those of Psenes cyanophrys showed a most conspicuous roundness at the head, a very fine mode of spination at the preopercular margin, and relatively small pelvic fins. 188 Bulletin of Marine Science of the Gulf and Caribbean [6(3)

FIGURE 2A-C. Psenes cyanophrys Cuvier and Valenciennes: A-2.5 mm specI- men; B-3.2 mm specimen; C-4.7 mm specimen. 1956] Legaspi: Life History of Psenes 189 Tables 2 and 3 show all the measurements and spiny and soft fin ray counts of all the specimens studied, and Table 4 gives the bodily proportions. The smallest specimen, 2.5 mm (Figure 2A), has presumably just completed the absorption of yolk. The snout is extremely short and blunt, 4.0 per cent of the standard length; the jaws equal, and the eyes are very large, 50.0 per cent of the head. The pectoral fins are set on a fleshy base and are rounded, with evidence of developing fin rays. The dorsal and anal fins are confluent with the rounded caudals presenting a continuous contour outline. Between the bases of the pectoral fins, rudiments of the pelvic fins are present. The vertebral column is straight and rod-like. Chromatophores are quite evenly distributed on the head and nape, scattering through the cheeks and operc1e. A few are also scattered at the base of the pectoral fins, on the sides of the body cavity and on the ventral side of the body to the tip of the vertebral column. The myotomes are indistinct. At 3.2 mm (Figure 2B), several changes are evident. Over the short size interval of 0.7 mm, development has progressively taken place. The body deepens dorsoventrally, assuming a more compact appearance. The snout is conspicuously longer, 41 per cent of the head, with two pairs of nostrils visible. The fine serrations on the preopercular margin are now distinctly spinous. The pectorals show more fin rays in evidence. There are spines developing on the dorsal and anal fins which are now differentiating from the expanding caudal fin. All the unpaired fins have the fin ray elements developed. The pelvic fins have grown but the ventral sheath is not yet visible. The urostyle makes its appearance with evidence of the hypurals ventral to it. The myotomes at the posterior region of the body are more evident, forming a zigzag pattern. The chromatophores are retained except on the preopercle, ventral side and tail. Those on the head form a crown. At 4.7 mm (Figure 2C), the fish assumes an adult-like appearance. The body tapers off posteriorly. The snout has decreased, 28 per cent of the head, approximating the juvenile proportions. The spines on the preopercular margin have grown but are distinctly weak. The second longest has made a downward bend giving the preopercular margin a characteristic pattern. The pectoral fins now have several fully formed fin rays with indications of more in formation. In the pelvic fin, a single spine is developing and fin ray elements are present. The dorsal and anal fins which have completely separated 190 Bulletin of Marine Science of the Gulf and Caribbean [6(3)

FIGURE 3D-F. mm speci- 1956] Legaspi: Lite History ot Psenes 191 from the caudals have developing spines, but none of the fin rays is completely formed. The caudal is well defined, rather truncate preparatory to forking. The chromatophores are concentrated on the head, abdominal wall and caudal base. A few are distributed on the sides. The anterior myotomes are now evident. At 6.9 mm (Figure 3D), the larval characters become exaggerated, while the adult characters make their first appearance. The mouth is oblique with the jaws bearing fine teeth. The eyes are relatively smaller. The preopercular spines are now at their longest stage. The longest spine slightly exceeds the subopercle. The previously rounded pectorals, which have an increased number of fully formed rays, show a tendency to become pointed. The dorsal and anal fins have expanded. Seven spines and twenty-two fin rays are fully developed in the dorsal fin. The dorsal sheath is evident. The pelvics are almost fully formed except for a complete adult fin ray count. The ventral sheath is also visible. Three spines and twenty-six rays are distinct in the anal fin. The caudal fin with fully developed middle rays has a shallow cleft giving it a slightly emarginate posterior margin. Adult pigmentation is becoming apparent. Chromatophores are evenly distributed throughout the body, slightly more close-set on the head and along the base of the dorsal and anal fins. There are no indications of the lateral line, but large chromatophores form a line on the mid posterior side of the body which gives the illusion of a lateral line. Over a size range of 2.5 mm (6.9-9.4 mm specimens), the ap- proximate adult proportions have been attained. The fish at 9.4 mm (Figure 3E) apparently starts a gradual change to juvenile form. The snout is much reduced. The preopercular spines have gradually shortened and are now half their length compared to those of the preceding fish. The pectorals are now assuming a more definite shape and ray counts are those of the adult. The dorsal and anal fins have the adult counts, 11 spines and 26 rays in the former, and 3 spines with the last spine attached to the first of the 26 rays in the latter. The pelvic fins are fully developed and distinctly smaller than the pectorals. The dorsal and pelvic sheaths are well developed. The pigmentation pattern of the adult is more pronounced. Chrom- atophores are distributed throughout the body concentrating in certain areas to form patches. The now completely developed caudal fin has a deeper cleft. The lateral line, however, is not yet discernible. Although there is a long size gap to the next available specimen, 192 Bulletin of Marine Science of the Gulf and Caribbean [6(3) 17 mm (Figure 3F), most of the larval characters are still evident. Through the 7.6 mm (9.4-17.0 mm specimens) size gap nearly all of the adult characters have taken over. The head has lost its over- sized larval appearance, but the depth has increased to 51 per cent. The mouth is more oblique; the jaws, almost equal, bear a single row of fine teeth. The snout is shorter and remains thus in the larger specimens. The preopercular spines have almost completely receded, leaving only a crenulate margin. All the fins are fully developed except for the elongation of the pectorals producing a slightly falcate form in the adult. The skin has a rather rough texture, probably due to the incipient cycloid scales which in the larger sizes are completely laid down. Adult pigmentation predominates. The chromatophore patches are much denser, forming interrupted bands. The lateral line has made its first appearance as a faint, slightly convex line above the median line. The young fish is essentially similar to the adult and may now be termed a juvenile.

Discussion. It has been frequently generalized in developmental studies that animals or plants of the same species are more highly developed at a smaller size in tropical than in temperate areas. Larval fish development would undoubtedly conform with this gen- eralization. However, no comparison can be made of Psenes cyanophrys, as this is a tropical and warm temperate species, and according to Longley and Hildebrand (1941) its northern limit is Florida. Nevertheless, even among closely related groups residing in the same locality, development proceeds at different rates. Voss (1954) found this to be true among her larval gempylids taken from the Florida Current and vicinity. From the overall study of the larval and juvenile stages of P. cyanophrys, development in the postlarval stage is noticeably rapid. In the 2.5 mm larva, all the fins are present, although rudimentary and not well differentiated. The pectorals are the most prominent of these fins. According to Regan (1916), the pectoral fins which are principally concerned with balancing are present in the youngest fish larvae. In order to show the changes that take place from the early postlarval to the late juvenile forms, a series of graphs were constructed using the bodily proportions of the thirty specimens studied. Figures 4 and 5 show the relationship of the various measurements to standard lengths, and in some cases to head length, of the specimens. 1956] Legaspi: Life History of Psenes 193 50

o ~o 0 o 00 40 p 0 ~0_8~ I 0 ~ 00 (1)--8- 0 I O-o-O~ , 0 ------0 : A I o 20

0 60 CI 00 osog~ 00 0 50 o 0 CI o 0- 0 000 0 0 C 40

10 D

STAN DARO LENGTH IN MM. FIGURE 4A-D. Bodily proportions of thirty specimens of Psenes cyanophrys Cuvier and Valenciennes: A-Head to standard length; B-Snout to standard length; C-Depth to standard length; D-Eyes to standard length. 194 Bulletin of Marine Science of the Gulf and Caribbean 60

A 40 A A lie i. ," AdinA A % I ;&-LA-6 A d to ----,6 I A 30 ,,I A E , 000 000 , o Qp 80----0-05'0-0 , (1)0 g 0 ° 20 ,I F f °

o 3 HEAD IN MM. FIGURE5E-F. Bodily proportions of Psenes cyanophrys Cuvier and Valencien- nes: E-Eye to head length; F-Snout to head length. In all the larval and juvenile specimens, the greatest depth is at the origin of the pelvic fins, and reaches its peak in the juvenile stage at about 21 mm (Figure 4C). The relationship of the eye to length does not show a postlarval or juvenile peak but presents a practically con- stant ratio throughout the entire size range (Figure 4D). The exaggerated characters which distinguish the postlarval stage are most pronounced over a range of about S mm, from the 4 mm to the 13 mm size stages (Figures 4A; 4B; SE; SF). At 17 mm, the young fish is distinctly a juvenile, and growth then proceeds until adulthood is attained. There is no true metamorphosis and development is direct. BIOLOGY Food. The author has been unable to find any mention in the literature concerning the food or feeding habits of this fish. All of the specimens reported on in this paper were later dissected. Most of the stomachs were found to be much distended, and upon examination of their contents, copepods appeared to constitute the basic diet, as in the case in many young fish. Table S lists the stomach contents of the postlarvae and juveniles examined. 1956] Legaspi: Life History of Psenes 195 TABLE 5 Stomach Contents of 30 Postlarval and Juvenile Specimens of Psenes cyanophrys. Standard length in mm Contents of Stomach 2.5 digested copepods 3.2 digested copepods 4.7 3 copepods 6.9 empty 9.4 5 copepods, 2 fish eggs 17.0 digested copepods 17.5 4 copepods, 1 chaetognath 18.0 8 copepods, 2 fish eggs 18.5 digested copepods 18.5 6 copepods 18.5 empty 19.0 empty 20.0 5 copepods, 4 chaetognaths 21.0 digested copepods 21.5 ] 0 copepods, 2 chaetognaths 21.5 4 copepods 22.0 digested copepods, 1 chaetognath 24.0 3 copepods, 3 chaetognaths 1 fish egg 25.0 digested copepod, ] fish egg 26.0 7 copepods, 3 chaetognaths 33.0 ]] copepods, 2 chaetognaths 1 fish egg, 1 fish larva 33.5 digested copepods 37.5 9 copepods, 1 amphipod 38.0 digested copepods 40.0 empty 40.0 6 copepods 43.0 4 copepods, 1 chaetognath 44.0 5 copepods 66.0 digested copepods

From the above table, it is seen that in the very small fish, the food is apparently mainly copepods, but with increase in size, there appears to be a mixed diet of fish eggs, fish larvae, amphipods and chaetognaths as indicated by the stomach contents. In most of the specimens only the exoskeletal remains of copepods were discernible, with the softer parts already in an advance state of digestion. The identifiable ones were mostly calanoids but they were in such poor condition that identification to species was not attempted. Eleven copepods was the largest number to be found in anyone larva. The only fish larva, 8.0 mm long, was taken in the stomach of a 33.0 mm juvenile. In all cases, from five to ten specimens of an internal parasite of some kind, 196 Bulletin of Marine Science of the Gulf and Caribbean [6(3) measuring from 0.5 mm to 2.0 mm in length, were found in the folds of the stomachs. Spawning. Very few adults of Psenes cyanophrys have been taken in the past and no gonadal studies have been carried out to determine the time of spawning. Gunther, however, had a series of specimens which he referred to as P. cyanophrys ranging in size from 24.0 mm to 74.0 mm, which presumably are late juveniles. They were taken from different localities: between Tenerife and St. Thomas; Gulf Weed, south of Bermuda; south of New Guinea; the Philippines; north of Papua; and Japan, during the months of February, March, April, May and August. Day's P. javanicus (=cyanophrys) was caught in October. This report includes the study of thirty postlarvae and juveniles of P. cyanophrys ranging in size from 2.5 mm to 66.0 mm standard length. They were collected from Caribbean waters between Grand Cayman and Cape Camaron (Honduras), the Straits of Florida, and the waters between the southeastern coast of Florida and the Ba- hamas, mainly in the Florida Current and vicinity (Figure 1). The specimens were taken in March, April, May, July, August and Octo- ber. Although the size ranges in the three localities are not uniform, being 4.7 mm-33.5 mm in length from the Florida coast and the Ba- hamas, 21.5-40.0 mm in length from the Straits of Florida, and 2.5· 66.0 mm in length from the Caribbean area, the wide distribution of the larvae and juveniles indicates that this fish spawns over an area of considerable extent. The lack of specimens of smaller size in the Straits of Florida may be due to poor sampling. Table 6 lists the length range and the corresponding time of the year the specimens were taken. TABLE 6 DISTRIBUTION OF LARVAE AND JUVENILES BY MONTHS OF THE YEAR OF Psenes cyanophrys. Month Length of Larvae January o February o March 9.4-18.0 April 2.5-66.0 May 6.9 June o July 18.5 August 17.0-33.5 September o October 4.7-18.5 November o December o 1956] Legaspi: Life History of Psenes 197 In the above table, it is shown that the postlarvae occurred in the areas mentioned from March to October except in June and Septem- ber. No prolarvae were taken; the smallest postlarva was 2.5 mm, probably in its earliest postlarval existence. The occurrence of juveniles in almost all the months that the species was taken apparently indicates that P. cyanophrys spawns in the Car- ibbean and Florida waters throughout the greater part of the year, mainly from late winter through fall. Vertical Distribution of the Young. The 30 postlarvae and juveniles included in this report were all taken from the surface waters (0 depth), and no vertical distribution nor movement can be shown. The juveniles, mostly, of Psenes eyanophrys together with those of Caranx ruber and Caranx bartholomei were frequently picked out from clumps of Sargasso weed by dip netting along the Florida Current. These fishes, along with certain other free-swimming animals, constitute part of the characteristic fauna of the floating Sargasso weed. This occurrence denotes a strictly pelagic existence, at least in the younger stage, as far as the population of P. eyanophrys in the Florida and Caribbean waters is concerned. However, more extensive collections may give more data on the vertical distribution of this fish. Hydrographic Conditions. The postlarvae and juveniles were taken in waters with a surface temperature ranging from 26.64°-28.8°C and a salinity range of 34.83-36.0%0' The narrow ranges of these figures can be applied only to the young since.we have no data concerning temperature and salinity tolerances for the adults. The early stages generally are the most critical period in the life history of marine animals as the sensitivity to environmental fluctuation is then generally greater than at any other period in their life span. SUMMARY 1. The family position of the genus and its occurrence in the trop- ics is discussed. Previous records of juveniles and adults of Psenes cyanophrys Cuvier and Valenciennes are given. 2. The materials and methods of collection and study of the postlarvae and juveniles of P. cyanophrys from the Caribbean Sea, Straits of Florida and Florida Current is summarized. 3. The taxonomic significance of larval characters is discussed. In P. cyanophrys, the preopercular margin with its mode of spination, the general round appearance and the fin ray counts are the taxonom- ically important larval and juvenile characters. 198 Bulletin of Marine Science of the Gulf and Caribbean [6(3) 4. A series of 30 post1arvae and juveniles of P. cyanophrys Cuvier and Valenciennes, ranging in size from 2.5 to 66.0 mm standard length, are described and illustrated. These are the smallest specimens of this species yet recorded. 5. The bodily proportions are presented in indices and graphs il- lustrating the gross morphological changes occurring through development and growth. The larval characters are most pronounced over a range of about 9 mm, from the 4 mm to 13 mm size stages. At 17.0 mm the young nomeid is distinctly juvenile, and growth then proceeds until adulthood is reached. There is no true metamorphosis and development is direct. 6. The general biology of P. cyanophrys based on available data on food, spawning and hydrographic conditions is discussed. This species is apparently a surface dwelling fish, living primarily upon planktonic forms such as copepods, amphipods, fish eggs and larvae and chaetognaths, in the younger stages. Spawning, as determined by the presence of young in all the months that the specimens of P. cyanophrys were taken, occurs from late winter to fall in Florida and Caribbean waters. The hydrographic data indicate a narrow range of tolerance for temperature and salinity in the young nomeids. LITERATURE CITED BALDWIN, W. 1954. A review of the family Carangidae and seven related families. pp. 6-7, (unpublished). BALINSKY 1948. On the development of specific characters in cyprinid fishes. Proc. zool. Soc. London. 118: 335-344. CUVIER, G. AND A. VALENCIENNES 1833. Historie naturelle des poissons, 9. Paris. DAY, FRANCIS 1888. The fishesof India, Ceylon and Burma, Part II. London. p. 237. DE BEAUFORT, L. F. AND W. M. CHAPMAN 1951. The fishes of the Indo-Australian Archipelago. 9: 88-89, Fig. 18. EIGENMANN, CARL 1902. Description of a new oceanic fish found off southern New England. Bull. U.S. Fish. Comm., 22: 35. FOWLER, HENRY W. 1906. Some cold-blooded vertebrates of the Florida Keys. Prec. Acad. Sci. Phila., 58: 119-121. 1936. The marine fishes of West Africa. Bull. Amer. Mus. nat. Hist., 70: 663. GOODE, G. B. AND TARLETON H. BEAN 1895. Oceanic ichthyology. Spec. Bull. U. S. nat. Mus., (2) :221. GUNTHER, ALBERT 1889. Report on the pelagic fishes. Rept. Sci. Res. Voy. H. M. S. "Chal- lenger." Zool., 31: 47. 1956] Legaspi: Life History of Psenes 199

HELA, 1., CHEW, F. AND L. P. WAGNER 1955. Some results of the oceanographic studies in the Straits of Florida and adjacent waters, 15 May, 1954 to 15 November, 1954. Tech Rept. 55, Office of Nav. Res., Mar. Lab. Univ. of Miami. HERRE, ALBERT W. 1953. Checklist of Philippine fishes. Res. Rept. 20, Government Printing Office, pp. 259-260. HUBBS, CARL L. 1929. Psenes cyanophrys, an oceanic fish, new for the fauna of the United States. Cooeia 171: 34-36. 1943. Terminology of early stages of fishes. Copeia 4: 260. JORDAN D. S. AND C. H. GILBERT 1882. Synopsis of the fishes of North America. Wash. Govt. Printing Office. KISHINOUYE, KAMAKICHI 1919. The larval and juvenile stages of the plecostei. Pac. Oc. Fish. Inv., U. S. Fish. Wildlife Ser., Dept. Int. Honolulu, Transl. 20: pp. 1-4 1950. Larval and juvenile skipjacks. Sp. Sc. Rept. 1919. U. S. Fish. and Wildlife Ser. pp. 1-14. LONGLEY, W. H. AND S. F. HILDEBRAND 1925. Systematic catalogue of the fishes of Tortugas, Florida. Carneg. Inst. Wash. Pub!. 34: 75. LUTKEN, C. 1880. Spoila Atlantica. K. Dansk. Selsk. Skrift (12) 6: 601-602. MEEK, S. E. AND S. F. HILDEBRAND 1925. The marine fishes of Panama. Field Mus. Nat. Hist. Zool. series, 15: 409-410. MILLER, R. R. 1946. Distribution records for North American fishes with nomenc1atorial notes on the genus Psenes. Wash. Acad. Sci. 36: 206-212. MII.LER, S. M., MOORE, H. B. AND K. R. KVAMMEN 1953. Plankton of the Florida Current. I. General conditions. Bull. Mar. Sci. Gulf & Caribbean. 3 (4): 465-485. MOORE. H. B. Ecology of marine animals. (In press). NORMAN, J. R. 1930. Oceanic fishes and flatfishes collected in 1925-1927. Discovery Rep. 2: 263-396. ORTON, GRACE L. 1953. The systematics of \'ertebrat~ larvae. Systematic Zoology 2 (2): 63-75. REGAN, C. T. 1916. Larval and postlarval fishes. Brit. Antarctica ("Terra Nova") Exped. Zool. 1: 125-155. Voss, NANCY A. 1954. The postlarval development of the fishes of family Gempylidae from the Florida Current. I. Nesiarchus Johnson, Gempylus Cuvier and Valenciennes. Bull. Mar. Sci. Gulf and Caribbean, 2 (4): 120-154. WEBER, MAX 1913. Die Fishe der Siboga Expedition. 57: 152-153. Leiden. WINN, H. E. AND R. R. MILLER 1954. Native postlarval fishes of the Lower Colorado River Basin, with a key to their identification. Cal. Fish and Game. 3 (40): 273-285.